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 Post subject: Cheap DIY intake setup
PostPosted: Mon Feb 16, 2009 5:06 pm 
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I knew there had to be a way to avoid cutting a hole in our hood. So I looked into aluminum piping elbows coming off the throttles then to the filters to lay them on their sides. Aluminum Piping seemed way to expensive about $45 Can for 1 U bend. Two are needed. Then you need the silicone couplers to attach to the throttles another $10-15 each. So I went to Home Depot just to see if they had anything that would work. I found some rubber elbows that are 2'' on the throttle side (what the busa is). Sure the tube tapers down to 1.5'' but is that really going to hurt power that much? Anyway they even came with hose clamps and are $10 each. The only other then thing needed is the little tube that goes into the filter in order to clamp the filter on it's $2 each. These pieces actually taper to 1.25'' so I "ported" them with a dremmel. Eventually I'd like to build a proper air box to develop some "ram air" effect but I think this current setup will work better then having them stick through the hood. The nice thing is with tubes being rubber they will flex so the hood can go on without a problem.

I should really lineup the clamps the same way to make it look a little tidier.

I've only got 3 done but here's the pics:

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PostPosted: Mon Feb 16, 2009 6:09 pm 
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Indeed a good design but I would make a box around the filters so that your getting cold air for ouside the hood instead of hot air around the engine.

Mines a middy so a ram air is just too simple not to build. That and the 07 R1 motors have electric variable velocity stacks so this wouldn't work.

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PostPosted: Mon Feb 16, 2009 8:10 pm 
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I do plan on a proper air box in the future. However there is not going to be a shortage of cold air the rad opening in the nose is quite large. I'm kind of hoping it will actually be somewhat of a positive pressure area as well. Variable trumpets sure would be nice to have but hard to work with.

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PostPosted: Mon Feb 16, 2009 8:51 pm 
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SR7 hopefull wrote:
Variable trumpets sure would be nice to have but hard to work with.


Agreed, its a cool feature but I would love to do the individual filters. If it was possible I would, but the design of the lower box would be way too crazy to do it. I plan to just remake the top half for one ram air scoop to fit between the headrests like the At-om... Just a bit smaller in size.

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PostPosted: Mon Feb 16, 2009 9:15 pm 
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I understand that Ram air is really important especially if your going to stay NA. My setup will probably consist of a tube running from the nose to a box with two inlets on it one for each set of two throttles. They will be separated in the middle so there will less volume for the air to fill thus producing higher pressure. The car scares me as it is so I look at this airbox as a power upgrade in the future.

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PostPosted: Mon Feb 16, 2009 9:16 pm 
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Those look like a good find. Are they just plumbing fittings? You should check them the first time or two they get really hot, just to make sure they don't soften too much. They look rugged though...

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PostPosted: Mon Feb 16, 2009 10:03 pm 
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No doubt ram air is nice and produces extra power by providing more air flow, but in my opinion is over rated. Everyone expects a huge boost in power but you just won't see that. My trans am ws6 had it and so did my R6, as well as my current R1. I have played around with them to see when you really feel the effect. Honestly ram air will give you like 1hp if lucky between 20-70mph. Above this is where you see it, but on a liter bike motor you won't see more then 1-3hp max at high speeds. Either way I'm looking forward to hearing the whistle of the air being sucked in right next to my head lol.

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PostPosted: Tue Feb 17, 2009 1:09 am 
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They will be separated in the middle so there will less volume for the air to fill thus producing higher pressure.


No need to worry about keeping the volume in the box small, in fact maybe the opposite. You want the cylinders to be able to pull a charge without emptying the box. If your running carbs, you need to include the float bowl vent in the box and injection needs to know this too.

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The car scares me as it is


Start working on a maniacal laugh (in private). :)

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PostPosted: Tue Feb 17, 2009 8:07 am 
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The air box should be between 65 and 85% of the volume of the actual engine. The higher the RPM the higher the percentage of volume for the required resonance. It's not that simple, you need to research intake systems to really optimize an ram/cold air box.

My engine likes cold AIR Dave W


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PostPosted: Tue Feb 17, 2009 12:27 pm 
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The air box should be between 65 and 85% of the volume of the actual engine. The higher the RPM the higher the percentage of volume for the required resonance.



This sounds more like a minimum then an exact range. Wouldn't a 2 cylinder have different requirements then an 8? I didn't expect to be tuning a resonance in the air box, just the intake runners, in which case you need a plenum enough bigger to decouple from the intake runners...

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PostPosted: Tue Feb 17, 2009 3:57 pm 
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horizenjob wrote:
Start working on a maniacal laugh (in private). :)


once he gets the car running and is comfortable with it... he should try the motor on two wheels :shock:

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PostPosted: Wed Feb 18, 2009 6:40 pm 
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I think that other the acceleration a "4 wheeled motorcycle" is definitely faster around a road course then a 2 wheeled one. As far as heat goes these plumbing pieces need to be "strong" enough for hot water and that's about as hot as the intake side of engine should get I would think. They are about 1/4'' thick on the ends. There will be a lot of air cooling as well so I will watch them but am not anticipating any problems. As far as volume for an intake goes it would seem to me that the stock bikes system has more then 1.3L of volume. I've heard a plenum should be twice the volume of the engine. It also depends on where you want your power to be. That's why variable trumpets makes sense they broaden the power band. Long at low speeds and short at High speeds.

Here's an article that I found on Ram Air the results may surprise you.
http://www.sportrider.com/tech/146_9912_ram/index.html

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PostPosted: Wed Feb 18, 2009 8:17 pm 
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If you want something more heat resistant yet still on the cheap, look at ABS plastic - can also be found at home depot/lowe's. ABS has a much higher melting point than PVC, which is what those "rubber" couplers are made of ;) . Fernco (the manufacturer of the ones at Home Depot) has a max recommended operating temperature of 140F non-consistant. BUT, your not going to be drinking out of your intake ;) . I haven't looked at any logs in a good long while, but I think its not too common to get intake temps a lot over that (like 180).

ABS lived in my DSM for a number of years, intake side of the turbo, hanging out millimeters away from the exhaust manifold and it never deformed.


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PostPosted: Wed Feb 18, 2009 9:50 pm 
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SR7 Hopeful wrote:
I think that other the acceleration a "4 wheeled motorcycle" is definitely faster around a road course then a 2 wheeled one.


Maybe a parking lot, but I wouldn't stand by that statement. Its really track, bike, and rider dependent. I'd put money on my R1(bike) with me at the handle bars around tracks like Laguna Seca, Willow springs, and Mid Ohio (all of which I have been to) over my soon to be R1 middy any day. On shorter courses I'd put money on the car.

Now a Hayabusa on the track... That's just a land boat (I'm a yamaha guy lol ). Joking aside I have seen them on the track and they can turn some good times.

Not trying to challenge you, but I have enough experience on bikes and racing at the track to know what I'm talking about.

SR7 Hopeful wrote:
Here's an article that I found on Ram Air the results may surprise you.
http://www.sportrider.com/tech/146_9912_ram/index.html


I don't argue those numbers at all because that's a HIGH SPEED test. I was merely basing my numbers off those that a car would see regularly (30-75) and tops (135). Testing them at top gear starting at 7000rpm on average those bikes gained 3-5 hp and a top of 8hp. That was a test between atmospheric pressure vs that at 155+ miles an hour. I wouldn't doubt my bike would pick up 5-7 at its top speed of 187mph. How often do you really think your car will hit speeds at which these numbers are relavent? Do a test of ram air at 30-75mph and see what power gains you see. Never did I say it was useless, but I said the gains are small.

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PostPosted: Thu Feb 19, 2009 1:27 am 
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I wonder how long those rubber hoses will withstand the suction without collapsing - especially in a hot engine compartment which will make them softer?

I cannot remember where, but semi-recently I saw a thread about a homemade CAI for some car that kept losing power and it turned out the rubber hose he used was collapsing at higher rpms (high flow).

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